Refrigerating device comprising a pressure compensation opening

ABSTRACT

A refrigerating device having a body and a door that enclose a refrigerated interior, have frame surfaces oriented toward each other and delimit a gap filled by a seal, the refrigerating device including at least one wall in at least one frame surface being forming with a passage therein, said passage being configured to bridge the seal, thereby allowing the interior to communicate with the environment.

The present invention relates to a refrigerating device, such as, say, arefrigerator or freezer, having a pressure compensation opening whichserves to prevent a negative pressure being generated in the interior ofthe refrigerating device.

Every time the door of a refrigerating device is opened, warm air entersits interior, cools down therein after the door is closed and generatesa negative pressure by means of which the door is sucked against thefront of the body. The effect of this negative pressure is that afterbeing closed the door is very difficult to open again until the pressurebetween the interior and the environment is equalized once more.Although a pressure equalization is in fact always reestablished after arelatively long time on account of the fact that the seal conventionallyfitted between the door and the front of the body of the refrigeratingdevice does not close so as to be completely airtight, efforts aregenerally nonetheless directed at keeping the leakage rate of said sealto a minimum, since air that is exchanged by way of leakages in the sealbetween the interior and the environment also always leads to anundesirable introduction of heat and humidity into the interior. Thehigher the precision with which the refrigerating device has beenmanufactured and consequently the smaller the leakage rate, the longerthe negative pressure persists after the door is closed.

This problem makes itself particularly clearly felt in the case ofrefrigerating devices in which the frame surfaces of body and door thatare disposed opposite one another and typically sealing off one anotherby means of a magnetic seal are embodied as a single piece and as aresult form a contact surface that is practically free of irregularitiesfor the magnetic seal and allows a very tight closure.

DE 102 33 216 A1 discloses a refrigerating device having an air passagewhich allows ambient air to enter the interior when the door is closed.The air passage of said known refrigerating device is provided in orderto prevent refrigerated items stored therein, such as, say, the corks ofwine bottles, from drying out. A secondary effect which is notconsidered in DE 102 33 216 A1 is that the passage prevents a negativepressure from being generated in the interior after the door is closed.The air passage of said known refrigerating device is implemented as abored hole which extends through a wall of the body or of the door. Apassage of said kind necessitates considerable manufacturing overhead,since its walls must tightly adjoin an inner and outer skin of the bodyor door in order to prevent insulating material that is being used tofill out the walls from escaping via the passage. The possibility ofaccommodating the passage in the magnetic sealing strip is cited as analternative. However, conventional magnetic sealing strips are notsuitable per se for enabling an opening to be formed therein.

An object of the present invention is to provide a refrigerating devicehaving a pressure compensation opening which, with minimal manufacturingoverhead, effectively prevents a negative pressure from being generatedafter the door is closed.

The object is achieved in that in the case of refrigerating devicecomprising a body and a door which enclose a refrigerated interior andhave frame surfaces that are oriented toward each other and delimit agap that is filled with a seal, a passage bridging the seal is recessedinto at least one of the frame surfaces, thereby allowing the interiorto communicate with the environment. Thus, instead of creating a passagein the body, in the door or in the seal in the conventional way, bymeans of the passage according to the invention a connection is createdwhich extends in each case between the seal and the body or between theseal and the door. Since no passage hole is formed, the sealing problemdoes not arise. The passage can be formed without additional overhead atthe same time as the frame surfaces of door or body are molded, inparticular by means of a deep-drawing process. The passage can have theshape of a trench, a channel or a plurality of interconnected trench orchannel sections.

In order to prevent as far as possible an exchange of air through thepassage which goes beyond the unavoidable amount due to the temperaturefluctuations of the interior, it is furthermore preferred that thepassage bridges the seal by a non-straight path.

A non-straight path of said kind can furthermore be considerably longerthan the width of the bridged seal, such that there is available in thepassage a large surface on which the moisture from the aspirated air cancondense. This reduces the probability that condensed moisture will fillthe cross-section of the passage and obstruct the flow of air in thepassage.

In order to achieve a passage of great length it can be provided inparticular that the passage includes at least one section running in thelongitudinal direction of the seal.

If the seal is fixed in a groove in one of the two frame surfaces, it isparticularly easy to form the passage on the other frame surface.

The passage can be formed on the same frame surface as the groove in aparticularly inconspicuous manner; in this case the groove extendsdiagonally across the passage, and at most the two ends of the passageare visible on different sides of the seal.

If a rib is formed in the base of the groove so as to engage in alongitudinal channel of the seal, said rib is preferably interruptedlocally in order to form the passage.

In addition, at least one end of the passage is preferably disposed at acorner of the frame surface, since the corners are generally the warmestareas of the refrigerating device housing and therefore the tendency toform condensate in the passage is relatively low at these points.

In order to prevent frost from forming in the passage and blocking it inthe course of the operation of the refrigerating device, the passage ispreferably heatable. Heating can be effected without additional costs bymeans of a frame heater which is provided in many refrigerating devicesin order to prevent dew from forming on outer surfaces of the body ordoor that are adjacent to the seal.

If the frame heater is formed by means of a refrigerant pipe extendingannularly in a discontinuous manner on the frame surface of the body,the passage is advantageously formed on the frame surface of the body atthe level of the interruption.

In addition to the passage, a pressure compensation valve extendingthrough a wall of the body or door can also be provided on arefrigerating device of the above-described type, which valve allows aninflow of air from the environment into the interior, but blocks anoutflow of air from the interior. Since a valve of said type prevents anuncontrolled exchange of air between interior and environment andconsequently an undesirable introduction of heat into the housing, itcan have a substantially greater free cross-section than the passagewithout appreciably increasing the inflow of heat to the interior andconsequently allow a faster pressure compensation than said passageafter the door is closed. It has been demonstrated that pressurecompensation valves of said kind tend to freeze up in continuousoperation, and that the presence of the passage removes this tendency tofreeze up.

Further features and advantages of the invention may be derived from thefollowing description of exemplary embodiments with reference to theaccompanying figures, in which:

FIG. 1 shows a schematic perspective view of a refrigerating deviceaccording to a first embodiment of the invention;

FIG. 2 shows a partial section through a wall of the body of therefrigerating device along the plane designated by II in FIG. 1;

FIG. 2 a shows a detail view of a corner of the body of therefrigerating device according to a variant of the first embodiment.

FIG. 3 shows a section through a pressure compensation valve;

FIG. 4 shows a bottom corner of the internal wall of a refrigeratingdevice door according to a second embodiment of the invention;

FIG. 5 shows a section through the internal wall and the sealing profilefixed therein along the plane designated by V in FIG. 4;

FIG. 6 shows a section along the plane designated by VI in FIG. 4;

FIG. 7 shows a perspective view of a corner of the internal wall of arefrigerating device door and a sealing profile accommodated thereinaccording to a third embodiment of the invention; and

FIG. 8 shows a section along the plane designated by VIII in FIG. 7.

FIG. 1 is a schematic perspective view of a refrigerating device havinga body 1 and a door 2 attached thereto which enclose a refrigeratedinterior 3. The walls of the body and the door each have, in a mannerknown per se, a solid outer skin and a solid inner skin which delimit anintermediate space filled with insulating foam material. The inner skinof the walls and a frame surface 5 surrounding the front opening of thebody 1 are formed in one piece from a plastic sheet in a deep-drawingprocess. A magnetic seal 4 is fixed in a manner known per se in a frontframe of the door 2 that is located opposite the front frame 5 when thedoor 2 is in the closed position. A passage in the form of a trench 8 isrecessed into the front frame 5 in such a way that when the door 2 isclosed, one end of the trench 8 comes to lie on the outside and theother on the inside of the seal 4.

FIG. 2 shows a section along the plane designated by II in FIG. 1through the trench 8 and its environment. In the sectional view shown inFIG. 2, two sections 15, 15′ of a pipe which acts as a frame heater canbe seen. The section 15 conducts warm, compressed refrigerant from acompressor (not shown) housed in a rear region of the body 1 and bendsadjacent to the trench 8 in order to extend along a bottom horizontalsection of the frame surface 5. The pipe runs along the entire framesurface 5 and finally arrives from above, as section 15′, at the trench8 once again, where it bends in the depth direction of the body 1 andruns onward to a condenser mounted externally on the rear wall of thebody 1. The frame heater thus extends annularly along the entire framesurface 5, with the exception of a gap between the two segments 15, 15′into which the trench 8 engages. Thus, the trench 8 does not obstruct arouting of the frame heater in direct contact with the frame surface 5.

The trench 8 shown in FIGS. 1 and 2 bridges the magnetic seal 4 in astraight line and at right angles. In order on the one hand to realize alow conductance value of the passage formed through the trench 8 and onthe other hand to be able to make the cross-section of the trench 8large enough so that not just a drop of condensed water will suffice toclose the trench 8, it is desirable to increase the length of the trench8, e.g. by its bridging the seal 4 at an acute angle, or, as shown inthe detail view of FIG. 2 a, by its comprising a section parallel to theseal 4 which runs inside an area of the frame surface 5 which is coveredby the seal 4 when the door 2 is closed and is delimited by dashed linesin FIG. 2 b.

The trench 8 can form the only passage between the interior 3 and theenvironment of the refrigerating device which supports a pressurecompensation between the interior 3 and the environment after the door 2is closed. According to a developed embodiment, a pressure compensationvalve is provided in addition for that purpose, for example in anopening 6 formed in the lower area of the door. An example of a possiblestructure of the pressure compensation valve is shown in FIG. 3, whichshows a perspective longitudinal section through the pressurecompensation valve 7.

A sleeve 11 secured in a foam-tight manner on the internal wall 10 bymeans of a bayonet joint extends between an exterior panel 9 of the door2 and an internal wall 10 deep-drawn from plastic. A membrane 12 heldunder flexural stress in the interior of the sleeve 11 has edges tightlyadjoining the walls of the sleeve 11 and is held in position by means ofan intermediate wall 13 extending transversely through the interior ofthe sleeve 11 and a cap part 14. In the event of a negative pressure inthe interior 3, air flows through between the edges of the membrane 12and the sleeve 11 in order to compensate for the negative pressure; apositive pressure in the interior 3, on the other hand, would press themembrane 12 against the sleeve 11, thus increasing the sealing effect ofthe valve 7; the pressure is therefore equalized by way of the trench 8.

If the valve 7 were provided as the only pressure compensation meansbetween the interior 3 and the environment, air from outside wouldslowly flow through the valve 7 when the interior 3 cools down in anoperating phase of the compressor. In this case there is a risk that theair will cool down sharply already when passing through the opening 6and moisture contained therein will condense out at the valve 7 and solead to the freezing of the valve 7. However, since the trench 8 isprovided according to the invention and contains no membrane obstructingthe air flow, in such a case the air will flow into the interior 3exclusively by way of the trench 8. Consequently the valve 7 cannotfreeze up, and the trench 8 is protected against freezing up by virtueof its close proximity to the frame heater 41.

FIG. 4 is a perspective view of a bottom corner of the internal wall 10of the door 2 as well as of the magnetic seal 4 secured to the internalwall 10 according to a second embodiment of the invention. In thissecond embodiment, the trench 8 on the frame surface 5 of the body 1 isreplaced by a corresponding trench 8′ formed on the frame surface of theinternal wall 10, two ends of which can be seen in FIG. 4.

On a rear face of the magnetic seal 4 facing away from a chambercontaining a magnetic strip 16 there are formed two projections 17, 18,of which one, 17, is populated by barbed hooks. The projections 17, 18engage in a groove 19 of the internal wall 10 which is subdivided intoan inner and an outer section 21, 22 by means of a rib 20 running in thelongitudinal direction of the groove 19. The barbed hooks of theprojection 17 are locked in place on undercuts of the inner section 21.A transverse wall 23 extending in the width direction of the magneticseal 4 and bulging forward into the section 22 is held by means of thelocking mechanism in a flexurally loaded position in which it holds theprojection 18 pressed into the outer section 22 of the groove 19. Athin, flexible wall section 24 of the magnetic seal 4 is bent inward byan edge of the outer section 22, such that the wall section 24 restsessentially tightly against this edge. Formed on an opposing edge of thetransverse wall 23 is a lip 25 which is pressed tightly against ashoulder 26 of the internal wall 10 adjoining the inner section 21 bymeans of the locking mechanism of the projection 17. The wall section24, the lip 25 and the barbed hooks of the projection 17 form aplurality of sealing lines between the internal wall 10 and the magneticseal 4.

However, said sealing lines do not extend over the entire length of themagnetic seal 4, but are interrupted by the trench 8′ at the corner ofthe door 2 shown. The trench 8′ is formed by an indentation in theinternal wall 10 being drawn at the point where a horizontal and avertical section of the groove 19 meet. An outer contour 28 of saidindentation can be seen in FIG. 5, which shows a section through theinternal wall 10 and the magnetic seal 4 along the plane designated by Vin FIG. 4.

FIG. 6 shows a section along the sectional plane inclined at 45° to thehorizontal and designated by VI in FIG. 4. The sectional plane runsalong the trench 8′, and it can be seen that neither the wall section 24nor the barbed hooks or the lip 25 touch the internal wall 10 along saidsectional plane. A passage extending between the magnetic seal 4 and thedoor 2 is created by means of said trench 8′.

The trench 8′ allows a pressure compensation between interior andexterior while bypassing the pressure compensation valve 7, although thecourse of the trench 8′ frequently changing its direction in the mannerof a labyrinth seal limits the exchange of air between interior andexterior to the degree necessary for the pressure compensation. Since onthe one hand the trench 8′ is heated by means of the front 5 and on theother hand air which has passed the trench 8′ must still pass atemperature-compensating gap 29 between the internal wall 10 and theframe surface 5 before reaching the interior 3, there is no risk of thetrench 8′ becoming blocked due to excessive condensation.

A third embodiment of the invention is described with reference to FIGS.7 and 8. Like FIG. 4, FIG. 7 is a perspective view of a corner of theinternal wall 10, wherein the groove 19 of the internal wall 10 is shownfitted with the magnetic seal 4 only on one part of its length in orderto be able to show a cutout 30 formed in the rib 20 separating thesections 21, 22 of the groove 19 from each other. The cross-sections ofthe groove 19 and the magnetic seal 4 are the same as shown in FIG. 5.As can be seen with reference to the section of FIG. 8 analogous to FIG.6, the passage 8′ is interrupted by the rib 20 in the sectional plane ofsaid figure. As can be seen with reference to FIG. 5, however, in bothsections 21, 22 of the groove 19 there are in each case longitudinalchannels 31, 32 delimited by the walls of the groove 19 on the one handand by the magnetic seal 4 itself on the other hand, of which onechannel 31 communicates with the environment at the level of the cornershown in FIG. 7 via an external section 33 of the passage 8′ (see FIG.8) and the other channel 32 communicates with the interior 3 via aninternal section 34 of the passage 8′. The two longitudinal channels 31,32 are connected to each other via the cutout 30. Since the cutout 30 isdisposed at a great distance from the corner in which the two sections33, 34 are disposed, the length of the entire passage 8′ can easily bemade greater than the edge length of the door 2. In an extreme case thecutout 30 could even be formed at the corner of the door 2 diametricallyopposite the corner shown in FIG. 7. In spite of a possibly largecross-section of the individual sections of the passage, the greatlength of the passage 8′ results in a low conductance value by means ofwhich an exchange of air between the interior 3 and the environmentwhich goes beyond the amount caused by temperature fluctuations of theinterior 3 is reliably suppressed.

1-11. (canceled)
 12. A refrigerating device having a body and a doorthat enclose a refrigerated interior, have frame surfaces orientedtoward each other and delimit a gap filled by a seal, the refrigeratingdevice comprising at least one wall in at least one frame surface beingforming with a passage therein, said passage being configured to bridgethe seal, thereby allowing the interior to communicate with theenvironment.
 13. The refrigerating device according to claim 12 whereinthe passage extends through the frame surface in a non-linear path. 14.The refrigerating device according to claim 12 wherein the passageincludes at least one section extending in the longitudinal direction ofthe seal.
 15. The refrigerating device according to claim 12 and furthercomprising a heater mounted at a front of the body wherein the passageextends through an area of the housing heated by the heater.
 16. Therefrigerating device according to claim 12 wherein the seal is fixed ina groove formed in a first one of two frame surfaces and the passage isformed on the second one of two frame surface.
 17. The refrigeratingdevice according to claim 12 wherein the seal is fixed in a groove ofone of the two frame surfaces and the passage is formed on the sameframe surface as the groove to extend between the walls of the grooveand an anchoring section of the sealing profile engaged in the groove.18. The refrigerating device according to claim 17 wherein the groove istransversely divided by a rib which engages in a longitudinal channel ofthe seal, and wherein the rib has a cutout through which the passageextends.
 19. The refrigerating device according to claim 12 wherein atleast one end of the passage is disposed at a corner of a frame surface.20. The refrigerating device according to claim 12 and furthercomprising a frame heater disposed on a frame surface of the body. 21.The refrigerating device according to claim 20 wherein the frame heateris formed using a refrigerant pipe extending annularly in adiscontinuous manner on the frame surface of the body thereby definingan interruption of the refrigerant pipe, wherein the passage is formedon the frame surface of the body generally at the level of theinterruption.
 22. The refrigerating device according to claim 20 andfurther comprising a pressure compensation valve extending through awall of at least one of the body and the door thereby proving an inflowof air from the environment into the interior and to thereby block anoutflow of air from the interior into the environment.